Hyperlipidemias: Grigore L

Grigore L, Norata GD, Catapano AL. · Department of Pharmacological Sciences, University of Milan, Milan, Italy. · Vasc Health Risk Manag. · Pubmed #18561502 links to  free full text

Abstract: Although widely used in lipid lowering therapy, HMG CoA reductase inhibitors (even when administered at high doses) are frequently insufficient to achieve guideline-recommended LDL-C goals for many patients with hypercholesterolemia in everyday clinical practice. Many patients do not achieve LDL-C goal on the initial dose of statin and the majority of these patients does not reach their goal after 6 months. As a consequence, a wide therapeutic gap exists between target LDL-C levels and those typically achieved in clinical practice. A recent and more effective therapeutic hypocholesterolemic strategy is to treat the two main sources of cholesterol simultaneously (production of cholesterol, mainly in the liver, and absorption of cholesterol in the intestine) with a complementary mechanism of action, by co-administering ezetimibe, a novel agent inhibiting cholesterol absorption, with a statin, which inhibits cholesterol production in the liver. Ezetimibe can be effectively and safely co-administered with any dose of any statin and, compared with the single inhibition of cholesterol production, afforded by statins alone, provides consistently greater reductions in LDL-C through dual inhibition of both cholesterol production and absorption. We summarize the pivotal role of both the liver and intestine in the overall balance of cholesterol in the body and describe the clinical impact and relevance of using ezetimibe either alone or co-administered with statins in controlling elevated levels of plasma LDL cholesterol.

Norata GD, Grigore L, Raselli S, Redaelli L, Hamsten A, Maggi F, Eriksson P, Catapano AL. · Department of Pharmacological Sciences, University of Milan,Via Balzaretti 9, 20133 Milan, Italy. · Atherosclerosis. · Pubmed #17055512 No free full text.

Abstract: OBJECTIVE: Triglyceride-rich lipoproteins (TGRLs) are a cardiovascular risk factor and induce endothelial dysfunction. In the present study, we investigated the effects of post-prandial TGRLs from type IV hyperlipidemic subjects on endothelial activation addressing the effects of the lipoproteins on intracellular pathways and gene expression. METHODS: Thirty fasted hypertriglyceridemic patients were given an oral fat load (OFL) and blood samples were collected before the OFL (T0) and 2, 4, 6 and 8h thereafter. Endothelial function, determined as flow-mediated dilatation of the brachial artery, was assessed at the same time points. TGRLs were isolated at T0 and T4 (PP-TGRL) for in vitro studies. RESULTS: Compared with TGRLs, PP-TGRLs induced to a larger extent phosphorylation of p38 MAPK, CREB and IKB-alpha in human endothelial cells and increased the DNA binding activity of CREB, NFAT and NF-kappaB. Furthermore, PP-TRGLs upregulated the expression of several pro-inflammatory genes including vascular cell adhesion molecule-1 (VCAM-1), PECAM-1, ELAM-1, intercellular adhesion molecule-1 (ICAM-1), P-selectin, MCP-1, interleukin-6 (IL-6), TLR-4, CD40, ADAMTS1 and PAI-1. CONCLUSION: These effects may relate to the severe impairment of endothelial function seen during the post-prandial phase in hypertriglyceridemic patients.

Maggi FM, Raselli S, Grigore L, Redaelli L, Fantappiè S, Catapano AL. · Department of Pharmacological Sciences, University of Milan, 20133 Milan, Italy. · J Clin Endocrinol Metab. · Pubmed #15181082 links to  free full text

Abstract: The objective of this work was to study whether changes in remnant lipoprotein (RLP) plasma levels during the postprandial phase relate to alterations of the endothelial function. Fasted patients (15 moderately dyslipidemic men) were given an oral fat load (OFL), and blood samples were collected before the OFL ingestion (T0) and 2, 4, 6, and 8 h (T2, T4, T6, T8) thereafter. Endothelial function, determined as flow-mediated dilatation (FMD) of the brachial artery, was assessed at the same time points. Triglyceridemia peaked between T4 (5.48 +/- 0.64 mmol/liter) and T6 (5.34 +/- 0.89 mmol/liter) and decreased at 8 h (4.36 +/- 0.87 mmol/liter) after the OFL. FMD decreased significantly 6 h after the OFL consumption (from 16.03 +/- 1.32% to 11.53 +/- 1.42%, P < 0.01). Cholesterol in RLPs increased steadily up to 6 h and decreased at 8 h (T0 0.53 +/- 0.10, T6 0.81 +/- 0.11, T8 0.73 +/- 0.13 mmol/liter). Fasting levels of triglycerides and cholesterol-RLPs (C-RLPs) correlated significantly with FMD at baseline. The decrease in endothelial function at 6 h also significantly correlated with the area under the curve of triglycerides (R = 0.53, P = 0.04). Postprandial C-RLPs (area under the curve), however, showed the best correlation with the decrease of FMD (R = 0.63, P = 0.012). The correlation persisted in a multivariate analysis. We concluded that C-RLPs contribute significantly to the endothelial dysfunction occurring during the postprandial lipemia.